Syringe assembly and attachment



' July 24, 1962 Filed Feb. 12, 1958 SYRINGE G. N. HEIN ASSEMBLY AND ATTACHMENT 2 Sheets-Sheet 1 BY KW, 4

ATTORNEYS y 1962 G. N. HEIN 3,045,673

I SYRINGE ASSEMBLY AND ATTACHMENT Filed Feb. 12, 1958 2 Sheets-Sheet 2 ite Sttes This invention relates to a structurally and functionally improved syringe assembly and an attachment for use in that assembly.

In its more specific aspects, the present application teaches an improved and/o1- alternative structure over that disclosed in my prior application for United States Letters Patent Serial No. 624,126 filed November 23, 1956, now Patent No. 2,952,255 and entitled Controlled Dosage Syringe.

It is a primary object of the invention to provide an assembly the several parts of which may be readily manufactured and coupled to each other to provide a stable structure which will function in a manner such that complete reliance may be placed thereon.

A further object is that of furnishing an attachment capable of ready application to or removal from a syringe barrel and plunger without affecting the sterility of the latter element. Moreover, the parts of the attachment may be easily cleaned, and if desired, separated. Thereafter, a person possessing no particular mechanical skill will be able promptly to effect a reassembly of the attachment parts and to apply that attachment to the plunger and barrel of a hypodermic syringe to normally maintain the plunger thereof in an elected retracted position.

With these and other objects in mind, reference is had to the attached sheets of drawings illustrating one practical embodiment of the invention, and in which:

FIG. 1 is a perspective view of a syringe and attachment, showing the latter being applied to the former;

FIG. 2 is a front view of the assembly;

FIG. 3 is a side view thereof;

FIG. 4 is a plan view of the unit as illustrated in the preceding figures;

' FIG. 5 is a partly sectional side view taken along the line 55 in the direction of the arrows as indicated in FIG. 2;

.FIG. 6 is a fragmentary enlarged sectional view taken along the line 6-6 in the direction of the arrows as indicated in FIG. 3;

FIG. 7 is a view similar to FIG. 6, but taken along the line 7-7 in the direction of the arrows as also indicated in FIG. 3; and

FIG. 8 is a transverse sectional view taken along the 8-8 in the direction of the arrows as indicated in FIG. 7.

In these views the numeral 10 indicates the barrel of a syringe, which, as illustrated, may be of conventional construction, and as such, be provided with an outer integral end wall formed with a bore and aligned tip portion defined by a fitting 11 of the Luer type. The open rear end of the barrel is provided with an outwardly extending flange 12. Reciprocal within the bore of barrel 10 is a plunger 13. The latter, in common with the barrel, may be formed of glass. This plunger has at its rear end an actuating or head portion 14. The face of the barrel is furnished with indicia, including gr-aduations 15 showing the volumetric capacity of the outer barrel end when the end 16 of the plunger is aligned with an elected graduation.

According to thepresent teachings, an attachment is provided for association with the syringe assembly and by means of which the plungerif not restrainedis retracted to a desired position spaced from the outer end Wall of the barrel. That attachment includes a yoke or mounting for coupling to the syringe barrel, which, as in FIG. 8, embraces a plate 17 formed with a notch 18 of a width such that the barrel 10 may be received therein. The width of this notch is, however, less than the dimension of flange 12. Adjacent opposite ends of plate 17, boss or mounting portions 19 (FIG. 7) provided. These, as illustrated, preferably have upwardly and outwardly inclined supporting surfaces 20 extending above the main surface of plate 17, so that in effect a recess is furnished between them. Within this recess the flange 12 is received.

Each of the mounting portions 19 is furnished with a bore of non-circular configuration. As illustrated, this bore is conveniently square. Slidably extending within it is a similarly square shank 21 terminating in each instance below a portion or boss 19 in a threaded extension 22. The latter supports a nut or screw-threaded cap 23 which bears against the underface of plate 17 in line with a boss 19. Shank 21 in each instance is continued beyond surface 20 of the boss mounting it in the form of an inwardly extending hook portion 24. The latter overlies the recess defined on the surface of plate 17 between the mounting portions 19. The distance between hooks 24 is less than the diameter of the barrel flange 12. Therefore, these hooks will have their ends overlapping the flange 12. Accordingly, upon the nuts 23 being tightened, and with the rear end of a syringe barrel having been introduced into notch 18 so that the flange of the former lies Within the recess of that plate, hook portions 24 will clamp the flange .12 against movement with respect to that plate.

A second yokeor support is provided to receive and cooperate with the actuating portion 14 of the plunger. This second yoke, as in FIGS. 4 and 6, includes a plate 25 also formed with a notch, as shown at 26. The width of this notch is greater than the diameter of plunger 13. However, it has a lesser dimension than the head or actuating portion 14. As shown particularly in FIG. 6, plate 25 may be dished so as to conform to a maximum extent with the contour defining the inner surface of head 14. A retaining element in the form of a spring 27 may, for example, be secured to an extension of plate 25 by a screw 28. The retainer clip or spring 27 is conveniently bowed upwardly, as at 29, adjacent its base portion, so as to clear plate 25 at that zone to a maximum extent. The tension on the spring should be such that its free end should be spaced from the plate a lesser distance than the thickness of the head or actuating portion 14 of the plunger.

1Interposed between the yokes defined by plates 17 and 25 are a pair of spring strips 30 which tend to assume a substantially flattened condition. The upper ends of these springs are formed with non-circular openings 31. Hook-shaped extensions 32 are preferably formed integral with plate 25 and extend downwardly therefrom. These extensions are also non-circular and have dimensions such that they extend through the openings 31 of the springs. Adjacent their lower or inner ends, springs 30 are also formed with non-circular openings. The area of the latter should approximate the area of the square bolts 21, which slidably pass through them. Therefore, with these shanks being held against swiveling with respect to boss portions 19, it follows that with the parts tightened, the springs 30 will intimately engage surfaces 20 and will not swing with respect to plate 17. Additionally, the lower ends of springs 30 will incline upwardly and exert a constant tension on shanks 21 as nuts 23 are tightened. Therefore, they Will prevent tendencies of the nuts or caps 23 to turn with respect to the extensions 22. Due to the preferably non-circular configurations of openings 31 and hooks 32, the springs will also prevent any tendency of plate 25 to oscillate around the axis of plunger 13. It is apparent that with the springs so disposed, the plunger will normally assume a retracted position.

In order to limit such retraction, stop means are provided. To this end a socket 33 may conveniently be integral with and define that extended portion of plate to which the inner end of spring 27 is secured. Fixed within this socket, preferably by means of the same screw 28 which anchors the spring, is the outer end of a rod 34. The latter has a length substantially equal to that of plunger 13 and is formed with a groove of diminishing depth in the direction of its free end. A second socket 36 is integral with or fixed against movement with respect to plate 17. Its bore is aligned with the bore of socket 33 and receives the free end of rod 34. Rod 34 may be manufactured of round stock. A collar 37 is slidably mounted upon the rod and formed with a threaded bore which receives the correspondingly threaded stem 38 of a set screw having a head portion 39. It is apparent that when the latter engages the end surface of socket 36 or its equivalent, further movements toward a separation of the plunger and barrel are prevented.

It is apparent that the several parts of the assembly may be readily produced. To group them together in proper relationship, it is necessary only to insert the hook-shaped portions 32 of plate 25 through the openings 31 at the upper ends of springs '30. The lower ends of the springs will be maintained in proper positions with respect to the yoke defined by plate 17 by passing the shanks 21 of hooks 24 through the openings in the lower spring ends. Thereupon, those ends may be anchored with respect to plate 17 by mounting the nuts or caps 23 upon the threaded extensions 22 and tightening the parts to a desired extent. The attachment is now ready for application to a syringe assembly.

That assembly will be in sterile condition. It is most important that such condition be not interfered with in grouping the syringe assembly with the parts of the attachment. According to the present teachings, this result may be achieved. With the collar 37 mounted on rod 34 and stem 38 projected so that it bears within groove 35, a detachment of the collar from the rod is prevented. Therefore the assembly is in the condition illustrated in FIG. 1. Now, by merely gripping the exterior surface of the syringe barrel and introducing its actuating or head portion 14 into the notch 26, it will be found that this portion will underlie the free end of the spring or clip 27. The parts may now be relatively rocked, so that the syringe assumes a position substantially parallel to rod 34. In such position the flange 12 of the barrel will come to rest Within the recess defined on the upper surface of plate 17 between the hooks 24. The free ends of the latter will thus overlie flange 12. Accordingly, by now finally tightening the nuts or caps 23, the hooks may be shifted to the positions illustrated in FIG. 7, in which flange 12 is clamped against movement with respect to plate 17. During the aligning of the syringe assembly, movement of the actuating portion or head 14 with respect to plate 25 may readily occur, incident to the fact that the outer end of spring 27 will engage the upper surface of the head as the latter is swung, and that spring or clip will be flexed outwardly to allow the actuating portion 14 to assume a position within the cup defined by plate 25. In occupying that position, it is apparent that the spring will be placed under tension. So disposed, it will bear intimately against the plunger and force its head portion into firm contact with the surfaces of the upper yoke, so that no movements will occur on the part of that plunger relative to such yoke. Accordingly, the piston will maintain the undersurfaces of its head portion in contact with plate 25 whether or not the operators hand or thumb is in engagement with the outer end of the plunger.

Now, by swinging the barrel inwardly, and as aforedescribed, it will be secured against movement with respect to plate 17. Accordingly, with the constant pressure exerted by clip or spring 27 against the plunger head, the alignment of the syringe parts of the assembly is maintained. Therefore, there will be no danger of the plunger tending to cock with respect to the bore of the barrel. Accordingly, reciprocation of the plunger within the barrel may occur freely without the necessity of overcoming excess friction of the parts, such as would occur if misalignment were a fact.

As will be understood by those conversant with the hypodermic syringe art, an assembly such as the present will frequently be used with a housing containing valves past which liquid may be drawn into the interior of the syringe barrel. Those valves will thereupon respectively seat and unseat, so that with a projection of the plunger, liquid is distributed as desired by the attending physician or surgeon. A hypodermic needle will also usually form a part of the assembly. These units have not been illustrated, since the present invention is primarily concerned merely with the syringe assembly and the attachment which makes that assembly possible. Having in mind the foregoing procedure to be followed after the attachment, barrel and plunger have been properly secured with respect to each other, an operator will assure himself that a proper volume of fluid will be drawn into the syringe barrel by the rearward stroke of the plunger.

The recommended procedure to be followed will preferably involve projecting the plunger to its fullest extent. This will serve to bow the springs 30 to a maximum degree. With collar 37 in position upon the rod, the collar is now brought to a point immediately adjacent socket 36 or its equivalent. Thereupon, bolt 38 is tightened so that its lower end bears within the surfaces of groove 35. It will be remembered that in applying the attachment, the user has merely grasped the exterior of barrel 10. Therefore, the plunger surfaces and the mounting 11 of the barrel will not have been rendered non-sterile. The same condition will be maintained as the parts are adjusted. Such adjustment will involve merely a determination of the volume of liquid to be drawn into the barrel upon the return or aspirating stroke of the plunger. This having been ascertained, by merely slightly loosening the stem '38 through turning the head 39, the tractive force exerted by springs 30 on the yoke defined by plate 25 will cause the latter to draw plunger 13 rearwardly within the bore of the barrel. According to the speed of loosening of the bolt or stem 38, the speed of this retraction will be varied. It may be controlled with precision. When the outer end 16 of the plunger has reached a point adjacent the graduation 15 which has been elected, no further loosening of the bolt is resorted to. Accordingly, the collar 37 may not move in a direction toward the free end of rod 34. Therefore, plunger 13 may not shift outwardly from the barrel beyond the defined position.

It is conceivable that under certain conditions of use, collar 37 might slide along rod 34 toward the upper yoke as defined by plate 25. Ordinarily, however, this will not occur. Should such movement come into being, the accuracy of the device will be in no way affected, because as the plunger moves outwardly from the barrel, collar 37 will continue to slide along the rod 34 until bolt or stem 38, riding within groove 35, encounters the shallower position of the groove corresponding to the position which the end 16 of the plunger is to assume within the barrel in its most retracted condition. At that point, retraction of the plunger will stop. Obviously, as the plunger is pushed forwardly by the thumb or otherwise, the liquid contained within the barrel will be expelled therefrom past the fitting 11.

Despite the fact that rod 34 is conveniently made of round stock, no turning of the collar 37 with respect thereto will occur. This is because stem 38 is riding within groove 35 and will therefore prevent such turning. Also, as afore brought out, springs 30 will maintain their positions at substantially diametrically opposite points in the assembly free from any swinging movements around the axis of that assembly. Thus, no concern need be felt that the bolts or tightening screws will fail to secure the ends of the springs against oscillation with respect to parts mounting the same. However, the mounting of these springs will be such that especially adjacent their upper ends they may have free swinging rznsovement around the parts connecting them to the plate Thus, among others, the several objects of the invention as specifically aforenoted are achieved. Obviously numerous changes in construction and rearrangements of the parts might be resorted to without departing from the spirit of the invention as defined by the claims.

I claim:

1. A mechanism to control the dosage dispensed by a syringe assembly which includes a barrel and a plunger reciprocal within said barrel, said mechanism comprising in combination a mounting to be applied to the barrel of the assembly, a support for association with the outer end of the plunger forming a part of that assembly, resilient means extending between and connected to said support and mounting to urge the same in opposite directions away .from each other, a rod element, a fixed element having an opening through which the rod extends and with respect to which said rod is slidable, one of said elements being connected to said mounting, the other of said elements being connected to said support, said rod being formed with a groove having a stop-forming surface therein which decreases in depth towards one end of the rod and a stop member mounted by said rod and having a stop-forming surface projecting into said groove to engage the stop-forming surface therein, said stop member being cooperable to limit the opposite movement of said mounting and support relative to each other.

2. In a mechanism as defined in claim 1, said rod element being connected to said support, said stop member being connected to said mounting, said stop member being shiftable along said rod and adjusting means carried by said member and projectable into frictional contact with surfaces of the groove to secure said stop member against such shifting.

3. An attachment for a syringe, including in combination a pair of yokes, means for securing one of said yokes adjacent the open end of a syringe barrel, a structure carried by the second yoke to attach the latter to the end portion of a syringe plunger, one of said yokes being formed with an opening, a rod carried by the second of said yokes and slidably extending through said opening, said rod being formed with a groove decreasing in depth toward one of its ends, a stop member slidably supported upon said rod and adjustable means carried by said member and bearing within said groove to engage the base of the latter and limit the movements of said yokes with respect to each other.

4. In an attachment as defined in claim 3, spring means acting against and connected to said yokes to urge them in opposite directions.

5. The combination with a syringe of the type having a barrel with an open end and a flange disposed therearound and also having a plunger reciprocal within the barrel with an outwardly projecting handle portion of a control device for controlling the size of the dosage to be administered by the syringe, said control device comprising: a first mounting member having a laterally opening notch terminating in a recess of sufficient size to accommodate the syringe barrel and having clamping means for engaging the flange on the barrel to hold the mounting member in place; a second mounting member having a laterally opening notch in alignment with the notch on the first mounting member and terminating in a recess of sufficient size to accommodate the handle portion of the plunger and having clamping means for holding the said second mounting member in place on the plunger; spring means connected between said mounting members to urge them apart; and stop limit means including a rod extending between the mounting members and connected to one of said mounting members and slidable with respect to the other mounting member to limit the movement of said mounting members away from each other, said spring means and rod being circumferentially oflset with respect to said notches to afford access thereto so that the control device may be assembled with the syringe by inserting the syringe barrel and plunger through the notches into the said recesses.

6. The combination with a syringe of the type having a barrel with an open end and a flange disposed therearound and also having a plunger reciprocal within the barrel with an outwardly projecting handle portion of a control device as set forth in claim 5 in which the rod is disposed diametrically opposite to the notches and the spring means are outwardly bowed leaf springs arranged in diametrically opposite relationship to each other intermediate the notches and the rod.

7. The combination with a syringe of the type having a barrel with an open end and a flange disposed therearound and also having a plunger reciprocal within the barrel with an outwardly projecting handle portion of a control device as set forth in claim 5 in which the spring means are outwardly bowed leaf springs formed with non-circular apertures at their opposite ends and the springs are attached to the mounting members by means of correspondingly shaped prongs extending through the non-circular apertures so as to prevent the springs from tilting.

8. The combination with a syringe of the type having a. barrel with an open end and a *tlange disposed therearound and also having a plunger reciprocal within the barrel with an outwardly projecting handle portion of a control device as set forth in claim 5 in which the rod is provided with a longitudinally extending groove which decreases in depth towards one end thereof and a longitudinally adjustable stop collar is mounted on the rod and is provided with an adjustable screw which engages in the groove to retain the collar in longitudinally adjusted position, said collar being engageable with the mounting member with respect to which the rod is slidable so as to limit the amount of separation between the mounting members.

References Cited in the file of this patent UNITED STATES PATENTS 2,198,666 Gruskin Apr. 30, 1940 2,823,674 Yochem Feb. 18, 1958 2,863,452 Ogle Dec. 9, 1958 

